Commit 9fe5ff1c authored by Steve French's avatar Steve French
Browse files

smb3: do not send compression info by default 



Since in theory a server could respond with compressed read
responses even if not requested on read request (assuming that
a compression negcontext is sent in negotiate protocol) - do
not send compression information during negotiate protocol
unless the user asks for compression explicitly (compression
is experimental), and add a mount warning that compression
is experimental.

Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
Reviewed-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
parent 412094a8

fs/cifs/cifsglob.h

+1 −0
Original line number Diff line number Diff line
@@ -601,6 +601,7 @@ struct smb_vol { 
	__u64 snapshot_time; /* needed for timewarp tokens */

	__u32 handle_timeout; /* persistent and durable handle timeout in ms */

	unsigned int max_credits; /* smb3 max_credits 10 < credits < 60000 */

	__u16 compression; /* compression algorithm 0xFFFF default 0=disabled */

};



/**

fs/cifs/connect.c

+8 −0
Original line number Diff line number Diff line
@@ -97,6 +97,7 @@ enum { 
	Opt_persistent, Opt_nopersistent,

	Opt_resilient, Opt_noresilient,

	Opt_domainauto, Opt_rdma, Opt_modesid,

	Opt_compress,



	/* Mount options which take numeric value */

	Opt_backupuid, Opt_backupgid, Opt_uid,
@@ -213,6 +214,7 @@ static const match_table_t cifs_mount_option_tokens = { 
	{ Opt_echo_interval, "echo_interval=%s" },

	{ Opt_max_credits, "max_credits=%s" },

	{ Opt_snapshot, "snapshot=%s" },

	{ Opt_compress, "compress=%s" },



	{ Opt_blank_user, "user=" },

	{ Opt_blank_user, "username=" },
@@ -1915,6 +1917,11 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, 
		case Opt_rdma:

			vol->rdma = true;

			break;

		case Opt_compress:

			vol->compression = UNKNOWN_TYPE;

			cifs_dbg(VFS,

				"SMB3 compression support is experimental\n");

			break;



		/* Numeric Values */

		case Opt_backupuid:
@@ -2691,6 +2698,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info) 
	tcp_ses->sequence_number = 0;

	tcp_ses->reconnect_instance = 1;

	tcp_ses->lstrp = jiffies;

	tcp_ses->compress_algorithm = cpu_to_le16(volume_info->compression);

	spin_lock_init(&tcp_ses->req_lock);

	INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);

	INIT_LIST_HEAD(&tcp_ses->smb_ses_list);

fs/cifs/smb2pdu.c

+12 −10
Original line number Diff line number Diff line
@@ -521,7 +521,7 @@ build_posix_ctxt(struct smb2_posix_neg_context *pneg_ctxt) 


static void

assemble_neg_contexts(struct smb2_negotiate_req *req,

		      unsigned int *total_len)

		      struct TCP_Server_Info *server, unsigned int *total_len)

{

	char *pneg_ctxt = (char *)req;

	unsigned int ctxt_len;
@@ -551,17 +551,19 @@ assemble_neg_contexts(struct smb2_negotiate_req *req, 
	*total_len += ctxt_len;

	pneg_ctxt += ctxt_len;



	if (server->compress_algorithm) {

		build_compression_ctxt((struct smb2_compression_capabilities_context *)

				pneg_ctxt);

		ctxt_len = DIV_ROUND_UP(

		sizeof(struct smb2_compression_capabilities_context), 8) * 8;

			sizeof(struct smb2_compression_capabilities_context),

				8) * 8;

		*total_len += ctxt_len;

		pneg_ctxt += ctxt_len;



		req->NegotiateContextCount = cpu_to_le16(4);

	} else

		req->NegotiateContextCount = cpu_to_le16(3);

	build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);

	*total_len += sizeof(struct smb2_posix_neg_context);



	req->NegotiateContextCount = cpu_to_le16(4);

}



static void decode_preauth_context(struct smb2_preauth_neg_context *ctxt)
@@ -829,7 +831,7 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses) 
		if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||

		    (strcmp(ses->server->vals->version_string,

		     SMBDEFAULT_VERSION_STRING) == 0))

			assemble_neg_contexts(req, &total_len);

			assemble_neg_contexts(req, server, &total_len);

	}

	iov[0].iov_base = (char *)req;

	iov[0].iov_len = total_len;

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